Knocking on start up

[woody-7]

Hello all, this is my first post on Renntech.

I hear knocking upon cold start up. It lasts for maybe a minute or less until the engine warms up then is gone and the engine sounds perfect and runs strong. I started noticing this when the temp outside is above 80.

Any ideas on what this could be?

I have always ran 93 octane for all 70000 miles. Think this may be a oil weight issue, I'm running 15w 50? What oil weight should I run in the summer and could this possibly be the problem?

99 996 cab.

Thanks for any help.

Edited April 21, 2006 by woody-7

[Loren]

Knocking or tapping like no oil in the lifters when cold?

If the knocking occurs with a warm engine that is not good.

[woody-7]

Knocking or tapping like no oil in the lifters when cold?

If the knocking occurs with a warm engine that is not good.

Thanks Loren,

I would say more like tapping. It goes away once the engine is warm.

I assume this is nothing to worry about.

[Loren]

Just the hydraulic lifters - normal.

[eben]

I have had a tick tick tick from one side only after having not run the engine for a few weeks.

As Loren mentioned, it went away after warm up and was probably a hydraulic lifter that wasn't full of oil.

Tick tick tick.... OK knock knock knock..... bad

Eric

:beer:

[armandodiaz]

Think this may be a oil weight issue, I'm running 15w 50? What oil weight should I run in the summer and could this possibly be the problem?

99 996 cab.

Thanks for any help.

Not sure where you live, but if FLA, Porsche recommends Mobil 1 0X40

[1999Porsche911]

Think this may be a oil weight issue, I'm running 15w 50? What oil weight should I run in the summer and could this possibly be the problem?

99 996 cab.

Thanks for any help.

Not sure where you live, but if FLA, Porsche recommends Mobil 1 0X40

Your tapping (if atributed to oil loss to the lifters) will be intensified changing to 0W40. Stick with the 15W50 or 5W50.

[El Acura]

Knocking or tapping like no oil in the lifters when cold?

If the knocking occurs with a warm engine that is not good.

Hi Loren.

Sorry to bring back and old post, but what could be the cause

if the knocking occurs when the engine is warm?

Could it be only bad gas.

Thanks

[Loren]

Knocking or tapping like no oil in the lifters when cold?

If the knocking occurs with a warm engine that is not good.

Hi Loren.

Sorry to bring back and old post, but what could be the cause

if the knocking occurs when the engine is warm?

Could it be only bad gas.

Thanks

Tapping could still be lifters or a stick lifter.

Knocking could be bad gas - but that is usually associated with rough running.

A really bad knock could be an IMS about to go.